The Chinese rover of the Chang’e 4 mission is scheduled to land on the far side of the Moon on January 3rd. The communication and data transfer tests between the Queqiao satellite, the Chang’e 4 probe and the Earth proceeded as expected. All the lights are green for this world premiere.
Since December 13, the Chinese probe Chang’e 4 revolves around the Moon. Although mission officials have not officially announced when the rover will land, most experts expect it to take place during the first days of January, possibly as early as January 3rd.
This date is the beginning of a 14 day period during which the landing site area will be constantly illuminated by the Sun. This permanent sunshine should allow the solar panels of the rover to work as soon as they are deployed and the batteries to recharge as soon as it is turned on.
The landing site is located at the Aitken Basin, located at the South Pole. It is an old impact crater with a width of 2,500 kilometers and a depth of 12 kilometers. Within this area, the crater subsequently formed, named Von Kármán, with a diameter of 186 kilometers should be the target of the lander. This region of the Moon is of great interest as it could contain exposed materials from the upper mantle of the Moon. Despite the proximity of the Moon to the Earth, its hidden face is little known to scientists and all expect interesting discoveries. If we had to make an analogy with the Earth, the Chinese mission is to land on a new continent of a known planet.
To provide telecommunications between the rover, its landing station and the Earth, China will use the Queqiao relay satellite. Launched in May 2018, it is today in orbit around the second Lagrange point (L2) of the Earth-Moon system located about 455,000 kilometers from our planet, which allows it to see the Earth and the hidden face of the Moon.
Note that NASA’s Lunar Reconnaissance Orbiter spacecraft should be able to identify the landing station, or even observe the tracks of the rover, if not itself.